1. Field of the Invention
The present invention relates to the deployment of automobile air bags and other dynamically deployed devices (xe2x80x9cDDDsxe2x80x9d), and more particularly, to a dynamically deployed device shield (the xe2x80x9cDDDSxe2x80x9d) that increases the protective impact surface of an automobile air bag or other DDD while covering, protecting, and guiding the deployment of the automobile air bag or DDD.
2. Background of the Invention
Dynamically deployed devices, such as automobile air bags, are widely used to protect vehicle occupants during rapid vehicle deceleration, such as the deceleration encountered in a collision. The DDDs used in vehicles are placed throughout the vehicle in strategic locations where occupants can be expected to impact hard components of the vehicle. Generally, DDDs are placed above and below the dashboard on both the driver and passenger side, and are placed along the sides of the vehicle at both head and hip levels. The lower DDDs protect the legs and hips of the occupant, while the upper DDDs cushion the head and upper torso.
During a collision, impact forces deform the vehicle structure and push potentially harmful structural parts into the passenger compartment. During such deformation, parts of the vehicle structure can be severely bent or broken, threatening the safety of the occupant with sharp edges and hard surfaces. The DDD cushions the occupant against the impact and shields the occupant from the sharp edges and hard surfaces. However, the DDD itself is subject to damage from the deformed or broken structural components. Moreover, if the DDD is damaged during deployment by structural components, the DDD will not inflate properly, will not reach the desired fully deployed location, and will not prevent the occupant from striking the structural parts of the vehicle, such as the vehicle dashboard, windshield, doors, side windows, and roof. Thus, to ensure adequate performance of the DDD, the DDD must be shielded from the damaging structural components.
Aside from protecting the DDD and the occupant from harmful vehicle components, another aspect critical to occupant safety is the ability of the DDD to reach and remain in a position between the vehicle structure and the expected location of the occupant during the collision. Conventional DDDs tend to oscillate before settling into the designed deployment location. This oscillation is especially troublesome with tubular structures that are attached at only two ends when deployed, such as the typical design used for side impact protection. Because the DDD is anchored at its longitudinal ends, when the DDD deploys from the storage compartment, inflates, and moves toward a position centered between the anchor points, the DDD tends to overshoot its final deployment location and oscillate back and forth past its final deployment location.
The prior art does not overcome these problems. For example, U.S. Pat. No. 5,429,385 discloses a dashboard-mounted air bag device that uses either a protective cloth or restraint guide to keep the air bag from contacting and damaging the edge of the upper opening of the DDD storage compartment. The protective cloth and restraint guide keep the upper opening from interfering with the deployment of the air bag. However, because neither the protective cloth nor the restraint guide fully envelops the air bag, the device does not fully protect the air bag and does not limit the oscillation of the deploying air bag.
U.S. Pat. No. 5,385,366 discloses an air bag deflection shield for use in a panel-mounted air bag module. The shield is separate from the air bag cover door and is designed to direct the inflating air bag rearwardly and downwardly toward a vehicle occupant and to shield the cover door from contact by the inflating air bag. However, despite the shield, the air bag is still subject to damage from vehicle components and is not restrained against oscillation.
U.S. Pat. No. 5,149,130 discloses a protective, high temperature resistant fabric applied to the air bag to prevent damage to the portion of the inflatable cushion closest to the gas generator. Although the protective fabric prevents heat damage around the gas generator, the fabric does not protect against physical damage from harmful vehicle components in other areas of the air bag. Further, the protective fabric does not restrain the air bag to prevent oscillation.
U.S. Pat. No. 5,160,164 discloses a deflection device for an air bag assembly, which controls the inflation pattern of the air bag so that the air bag does not undesirably contact an occupant""s head before it contacts the occupant""s torso. The device controls the general deployment direction of the air bag but does not restrain the air bag at full deployment and, therefore, does not prevent oscillation. Further, the device does not protect the air bag itself against damaging contact with vehicle components.
The present invention is a protective assembly that enhances vehicle occupant protection by increasing the protective impact surface of a dynamically deployed device, such as an automobile inflatable tubular structure. The protective assembly, or dynamically deployed device shield, also provides an attractive housing for the DDD that transforms upon deployment into a shield that protects the DDD against damage by vehicle components, facilitates deployment of the DDD through vehicle trim and interior components, and limits the oscillation and overshoot of the DDD to optimize the protection of the vehicle occupant.
In a preferred embodiment of the present invention, the DDDS shields an inflatable tubular structure, e.g., the side-impact head strike protection structure described in U.S. Pat. No. 5,322,322, which is hereby incorporated by reference in its entirety. Other applications of the present invention include other styles of side-impact head strike and rollover counter measures, front air bags, torso side-impact airbags, and other dynamically deployed devices.
The DDDS comprises a loop shield, a cover, and a means for attaching the DDDS assembly to the vehicle structure. The loop shield is made of a protective material and is positioned to optimize its protective benefits to vehicle occupants without compromising its ability to wrap, restrain, and protect the DDD during deployment, particularly in areas where contact with damaging vehicle interior components is anticipated. The loop shield is attached to the vehicle structure by such means as stitching or mounting hardware. The loop shield has an interior volume that is larger than the volume of the inflated DDD, to hold the inflated DDD within a deployment location most favorable to the vehicle occupant. Thus, when the DDD is in its undeployed state, excess loop material must be gathered and secured.
The excess loop shield material is folded in an accordion fold, or other appropriate fashion, and placed against the DDD. The DDD and the folded loop shield are wrapped in an integral soft cover that is attached to the vehicle structure. The cover incorporates a perforated or stitched tear section that breaks away upon deployment of the DDD to allow both the loop shield and the DDD to expand.
The integral soft cover can be made of a separate piece of material or from the same material as the loop shield. To use the same continuous material of the loop shield, the integral cover is formed by folding back the loop shield material after the point at which it is stitched together and wrapping the loop shield and DDD again with the same loop shield material, but without accordion folds. In this configuration, because the integral cover is continuous to cover the entire length of the DDD and is formed from the same material as the loop shield, the loop shield must also be continuous, i.e., the loop shield is a continuous sleeve.
The loop shield is made of a thin, flexible material strong enough to withstand deployment and occupant contact forces. The preferred material for the loop shield is a woven fabric, such as nylon or polyester. Alternately, other thin, flexible materials are possible, e.g., plastic film and non-woven polyester. The length and width of the loop shield will vary depending upon the required zone of protection.
In a preferred embodiment of the present invention, the loop shield includes vents, e.g., holes, cuts, or slits, along the inboard or outboard side. These vents allow air to freely enter the interior of the loop shield as the loop shield is unfolding and expanding during deployment. The vents prevent a vacuum from developing inside the loop shield that could restrain the loop shield fabric and inhibit the DDD from reaching the intended final location. Further, a vacuum could draw the sides of the loop shield inward and reduce the distance of impact protection provided by the loop shield.
In a further preferred embodiment of the present invention, a fabric shield is attached to the bottom of the DDDS to further increase the protective impact surface of the system. This fabric shield covers the area of a vehicle window below the deployed DDD, reducing the possibility of partial ejection of vehicle occupant limbs and preventing entry of crash debris into the passenger compartment. The fabric shield connects to the bottom of the DDDS and extends to the belt line of the vehicle. A cord runs through the bottom of the fabric shield to draw it down to the belt line when the DDD is deployed. To develop tension and draw the fabric shield down, the fabric shield cord is attached at both ends to the top of the DDD and is routed around fixed points on the vehicle pillars such that when the DDD deploys, the ends of the fabric shield cord are pulled down, the cord travels around the pulleys, and the cord is drawn tightly along the horizontal belt line. With the fabric shield cord drawn tightly, the fabric shield is pulled down to the belt line. The fabric shield cord can be routed around fixed points on the vehicle pillars on one or both sides of the DDD.
In a preferred mode of the present invention, mounting hardware attaches the DDDS to the vehicle structure. Many variations of mounting hardware are possible and depend mostly on the structural requirements of the particular automobile. However, in one preferred embodiment, the DDDS material that forms the loop shield is continued beyond the point at which it is stitched in order to form an extra strip of material for a means of attachment. This extra material is referred to hereinafter as an attachment flap. The attachment flap has incremental holes along its longitudinal axis through which fasteners secure the DDDS to the vehicle structure. Once the loop shield material forms the attachment tab, the material is folded and continued again around the loop shield and DDD to form the integral cover.
An alternate preferred means of attachment uses a push-fitting stud plate, which comprises a long strip of rigid material with fasteners integrally attached at incremental points along its longitudinal axis. In this application, the flat side of the push-fitting stud plate is placed against the DDD, and the DDDS loop shield with the integral cover is wrapped around both the plate and the DDD. The DDDS loop shield and cover have holes through which the push-fitting stud plate fasteners extend and attach the whole assembly to the vehicle structure.
In some applications, inflatable tubular structures are attached at incremental, discrete locations with clips. Because the DDD is not continuously attached to the vehicle, attaching the DDDS at points between the clips would cause the entire DDD and DDDS assembly to pull away from the vehicle structure and xe2x80x9cbulgexe2x80x9d in an unsightly way. Therefore, in an application that uses incremental attachments such as plastic clips, spring elements and curved plastic strips can be added to more effectively contain the DDD and DDDS and eliminate the xe2x80x9cbulgingxe2x80x9d appearance. The spring element is preferably a metal piano-wire spring that attaches to the vehicle structure at the plastic clip locations and draws the DDD and DDDS assembly tight to the vehicle structure. Alternately, curved plastic strips also attached at the plastic clip locations restrain the DDD and DDDS assembly close to the vehicle structure.
The DDDS operates as follows. When the DDD is inflated, the expansion of the DDD results in forces that detach the cover at the tear section. The DDD further expands and causes the loop shield to unfold. During deployment, the loop shield provides a smooth surface within which the DDD can deploy, preventing the DDD from becoming snagged or caught on any vehicle interior features. As deployment continues, the DDD expands, develops tension, and pulls down and away from the vehicle structure. When the loop shield is completely unfolded, the loop shield restrains the DDD and controls the DDD""s ultimate orientation and position. The loop shield also limits the amount the DDD can overshoot its operational position, which in turn reduces or eliminates DDD system oscillation. When the DDD is in its deployed, functional position, the loop shield is under significant tension along its span, providing a tight protective impact surface for the vehicle occupant. In addition, with the preferred fabric shield attached to the bottom of the DDDS and pulled into position by the fabric shield cord, the fabric shield provides an additional protective impact surface from the bottom of the DDDS to the belt line of the vehicle.
Accordingly, it is an object of the present invention to enhance the occupant protection benefits of a dynamically deployed device by increasing the occupant impact surface area with a loop shield and a fabric shield.
Another object of the present invention to guide and control the deployment of a DDD.
Another object of the present invention is to protect the DDD while it is being deployed. For example, the invention can be used to prevent damage to the DDD by interior elements of a vehicle.
Another object of the present invention is to limit the DDD from overshooting its intended final position.
Another object of the present invention is to reduce or eliminate improper orientation, ;such as twisting, of the DDD.
Another object of the present invention is to reduce or eliminate oscillation of the DDD during deployment.
Another object of the present invention is to prevent crash debris from entering the vehicle and to prevent portions of occupants"" bodies from exiting the vehicle.
Another object of the present invention is to provide an aesthetically pleasing, integral soft cover for the DDD.
Another object of the present invention is to provide flexibility in positioning the DDD in order to provide maximum protection for a vehicle occupant.
These and other objects of the present invention are described in greater detail in the detailed description of the invention, the appended drawings, and the attached claims.